1. Field of the Invention
The present invention relates to an identification system for use in connection with the identification of motor vehicles. The vehicle identification system has particular utility in connection with law enforcement.
2. Description of Related Art
In the execution of their responsibilities to protect life and property, law enforcement officials must determine the registration and ownership of motor vehicles from the vehicle's license plate as quickly and safely as possible. Optical identification means historically used by these officials to determine the registration and ownership of motor vehicles adds to their burden to quickly resolve uncertain or dangerous situations. The current procedure limits the access to critical information because existing methods of determining a license plate number require visually reading the number from the plate, often from the rear of the vehicle. Optical or visual methods do not allow a rapid determination of a mismatch between the vehicle description and original registration or license information. In some circumstances, criminal intent, mud or poor lighting limits the visibility of license plate numbers.
Radio frequency identification techniques with compact, low-powered devices have long been known in the art. However, present devices and systems have deficiencies which hamper their effectiveness. Current approaches consist of a single tag and an interrogator. The current tags usually are small in size and transmit radio frequency electromagnetic signals at low power to extend the battery life. These approaches do not employ advanced signal techniques to thwart data errors caused by automotive electromagnetic interference or fading caused by multipath propagation. The small size of existing tags also results in an inefficient antenna. Tags with low power and inefficient antennae limit the transmission distance of the tag's transmissions to less than two hundred feet. Because the unaided eye can distinguish license plate numbers at similar ranges, the operation of an RF tag/interrogator system at these ranges does not provide any significant advantage over optical or visual techniques for determination of license plate numbers. In addition, current interrogators do not have means to distinguish the signals transmitted by multiple tags that receive the interrogator transmission or to consult local or remote databases. Further, the information transmitted by current tag systems is not secure, thereby permitting unauthorized people to access the personal information of a motor vehicle owner.
The need, therefore, exists for a tag/interrogator system which can safely and reliably improve the identification of motor vehicles.